Farmers' use of nets in jujube orchards has reduced spoiled fruit to only 5-10% compared to a loss of 30-40% at other orchards that use pesticides, according to the Ninh Thuan Province Department of Agriculture and Rural Development.
The nets are used during the fruiting period to protect the plant from pests, especially the Mediterranean fruit fly, and improve fruit yield and quality.
The Mediterranean fruit fly, or Medfly, is one of the most destructive pests to jujube and farmers normally use pesticides to kill them.
The eggs laid by female Medfly in soft-fleshed fruit develop into larvae, which eat the fruit pulp.
Jujube planted in net-covered orchards are sold at a price 1.5 times higher than fruit produced by normal orchards.
Several local farmers began using the nets in 2017. The net-covered model is now being used on nearly 55 ha of jujube, accounting for 5.3 per cent of the province's total jujube area, according to Pham Dung, head of the department’s Plant Cultivation and Protection Sub-department.
Vo Hieu, who uses nets to cover his 2,000 sq.m jujube orchard in Ninh Phuoc District, said that irregular weather had led to large quantities of Medflies which could not be eradicated by pesticides.
To protect his orchard from pests, Hieu spent VND20 million (US$860) to buy frames and nets last year.
Besides controlling pests, the nets also protect the fruit from strong winds and rains and the impact of strong sunshine.
The fruit quality has improved also because farmers now let the jujube ripe properly before harvesting them, he added.
The cost of nets is VND10 – 20 million ($430 - 860) per 1,000 sq.m. The net can be used for three to five years.
Jujube is one of the province’s 12 key agricultural products. The fruit has a light yellow colour when ripe, and is crunchy and sweet.
The province is piloting the cultivation of a new jujube variety called Táo Bom NT 05, which was created by the Nha Hố Research Institute for Cotton and Agriculture Development.
The new variety has a green colour when ripe and is two to three times larger than a normal jujube.
Farmer Trao Thi Tao, who is growing Táo Bom NT 05 in Phan Rang–Thap Cham City, said that harvesting is done after one year.
The new variety has a yield of 4 tonnes per 1,000 sq.m a crop, which is 1 to 1.2 tonnes higher than normal jujube varieties.
“It offers a profit nearly two times higher than normal jujube varieties,” she said.
The Nha Ho Research Institute for Cotton and Agriculture Development is teaching farmers how to grow the new variety. It targets increasing the growing area of the new jujube variety to 20ha next year.
The south central province, which is the country’s largest jujube producer, has more than 1,020ha of jujube, mostly in Ninh Phuoc, Ninh Hai and Ninh Son districts and Phan Rang – Thap Cham City.